Propellant variability assessment

Efforts to determine whether rocket propellant density and modulus can be reliably measured using non-destructive ultrasonic techniques are reported. The objective was not achieved, primarily due to the approach taken

Kartenlegenden mit der WRB 2015

Karten erfordern eine Generalisierung, sowohl bei kleinen als auch bei großen Maßstäben. In der dritten Auflage der World Reference Base for Soil Resources (WRB) von 2014, update 2015, sind vier Maßstabsebenen definiert, in denen die Böden in folgender Detailliertheit dargestellt werden: Erste Ebene: nur die Reference Soil Groups (RSGs). Zweite Ebene: RSGs und der erste zutreffende principal qualifier. Dritte Ebene: RSGs und die ersten beiden zutreffenden principal qualifier. Vierte Ebene: RSGs und die ersten drei zutreffenden principal qualifier. Die supplementary qualifier bleiben unberücksichtigt. In vielen Fällen sind auch einige principal qualifier unberücksichtigt, weil ein Boden ja mehr als die für die jeweilige Ebene zugelassenen principal qualifier haben kann. Einerseits stellen diese Regeln sicher, dass weltweit Karten nach demselben Prinzip erstellt werden und dass allgemein als wichtig angesehene qualifier in die Legendeneinheit eingehen. Andererseits können aber ausgerechnet die vernachlässigten qualifier Informationen beinhalten, die - je nach Zweck der Karte - von großer Bedeutung sind. Hierfür gibt es in der WRB eine Hintertür, die „optional qualifier“. Die WRB-Regeln erlauben, jeden beliebigen qualifier in Klammern hinter den Bodennamen zu setzen. Das können sowohl principal qualifier sein, die (auf der betreffenden Ebene) nicht Bestandteil des Bodennamens sind, als auch supplementary qualifier. Dieser Vortrag experimentiert mit den Möglichkeiten der optional qualifier. Sie sind oft bedeutsam für das Verständnis von Böden in der Landschaft und können dabei sowohl gemeinsame Eigenschaften von Böden unterschiedlicher RSGs ausdrücken als auch die Ergebnisse von lateralen Transportprozessen. Sie können über ein bestimmtes Stadium der Bodenbildung informieren. Und natürlich kann man mit ihnen Bodenfunktionen und -gefährdungen verdeutlichen

Spectral Imaging of Skin: Experimental Observations and Analyses

The emergence of compact optical spectral imaging technologies has motivated the study of their use in a variety of applications, including medical diagnosis and monitoring. In particular, large format CCD focal planes in conjunction with spectrally tunable devices offer enhanced spatial information together with visible and near infrared (NIR) spectroscopic data for the passive, noninvasive, measurement of human skin and near surface tissue characteristics. One such spectral imaging system was recently developed by mating a Liquid Crystal Tunable Filter (LCTF) together with a 2048x2048 silicon CCD focal plane. This system is capable of collecting more than 30 co-registered spectral images spaced every 10 nanometers and spanning 400 to 720 nanometers. This system combines the potential of near infrared diffuse reflectance spectroscopy with the high spatial resolution of traditional optical imaging techniques. Spectral images were acquired of portions of the hands and arms of several test subjects with a variety of features observable. The observations were collected in a light box under controlled illumination conditions. Images of a diffuse reflectance standard and instrument dark frames were collected to allow conversion of the raw images to spectral reflectance images. This paper presents examples of the spectral images collected, instrument characteristics and performance, and results of analysis algorithms applied to the data. Results also are shown for a new algorithm extracting the saturated oxygen hemoglobin fraction from these data

Spectral Imaging of Near-Surface Oxygen Saturation

A number of non invasive methods have been developed to characterize parameters in near-surface skin tissue; however, the work has usually been concerned with using either spectral or spatial information. This motivated our study in which both spatial and spectral data are used to extract features for characterizing the spatial distribution of near-surface oxygen saturation. This paper addresses combined physical and statistical models to retrieve the ratio of oxy- and deoxy-hemoglobin in tissues from data collected by an imaging spectrometer. To retrieve the oxygen saturation fraction from the data, algorithms from the literature using two or three wavelengths were compared to our new algorithm using the many more wavelengths (25 to 60) available in imaging spectrometer data, and noise reduction achieved through principal component transformations. In addition to the analysis of experimental spectral imagery, an oxygen saturation phantom of size 128x128 pixels was simulated. In the forward process, a reflectance image was constructed from an assumed oxygen saturation map and the absorption coefficients of oxy-hemoglobin, deoxy-hemoglobin, melanin and other chromophores. The reflectance data have 60 bands spanning 400 nm to 990 nm with 10 nm intervals in the spectral dimension. Varying amounts of white Gaussian noise was added to the reflectance data to simulate measurement errors in an actual experiment. In the backward process, an oxygen saturation image was reconstructed by applying the algorithm to study the effect of measurement error on the retrieved saturation fraction. The resultant images were evaluated by their mean squared error

Materials characterization on efforts for ablative materials

Experimental efforts to develop a new procedure to measure char depth in carbon phenolic nozzle material are described. Using a Shor Type D Durometer, hardness profiles were mapped across post fired sample blocks and specimens from a fired rocket nozzle. Linear regression was used to estimate the char depth. Results are compared to those obtained from computed tomography in a comparative experiment. There was no significant difference in the depth estimates obtained by the two methods

Removal of Spectro-Polarimetric Fringes by 2D Pattern Recognition

We present a pattern-recognition based approach to the problem of removal of polarized fringes from spectro-polarimetric data. We demonstrate that 2D Principal Component Analysis can be trained on a given spectro-polarimetric map in order to identify and isolate fringe structures from the spectra. This allows us in principle to reconstruct the data without the fringe component, providing an effective and clean solution to the problem. The results presented in this paper point in the direction of revising the way that science and calibration data should be planned for a typical spectro-polarimetric observing run.Comment: ApJ, in pres

Detection of Cellular Senescence Reveals the Existence of Senescent Tumor Cells within Invasive Breast Carcinomas and Related Metastases

Oncogene-induced senescence is thought to constitute a barrier to carcinogenesis by arresting cells at risk of malignant transformation. However, numerous findings suggest that senescent cells may conversely promote tumor growth and metastatic progression, for example, through the senescence-associated secretory phenotype (SASP) they produce. Here, we investigated the degree to which senescent tumor cells exist within untreated human primary breast carcinomas and whether the presence of senescent cancer cells in primary tumors is recapitulated in their matched lymph node metastases. For the detection of senescence, we used SA-β-galactosidase (SA-β-gal) staining and other senescence markers such as Ki67, p21, p53, and p16. In patients with invasive luminal A and B breast carcinomas, we found broad similarities in the appearance of cancer cells between primary tumors and their corresponding metastases. Analysis of lymph nodes from patients with other breast cancer subtypes also revealed senescent tumor cells within metastatic lesions. Collectively, our findings show that senescent tumor cells exist within primary breast carcinomas and metastatic lesions. These results suggest a potential role for senescent breast tumor cells during metastatic progression and raise the question as to whether the targeting of senescent tumor cells with anti-senescent drugs might represent a novel avenue for improved treatment of breast and other cancers

An open source software for analysis of dynamic contrast enhanced magnetic resonance images: UMMPerfusion revisited

Background: Perfusion imaging has become an important image based tool to derive the physiological information in various applications, like tumor diagnostics and therapy, stroke, (cardio-) vascular diseases, or functional assessment of organs. However, even after 20 years of intense research in this field, perfusion imaging still remains a research tool without a broad clinical usage. One problem is the lack of standardization in technical aspects which have to be considered for successful quantitative evaluation; the second problem is a lack of tools that allow a direct integration into the diagnostic workflow in radiology. Results: Five compartment models, namely, a one compartment model (1CP), a two compartment exchange (2CXM), a two compartment uptake model (2CUM), a two compartment filtration model (2FM) and eventually the extended Toft’s model (ETM) were implemented as plugin for the DICOM workstation OsiriX. Moreover, the plugin has a clean graphical user interface and provides means for quality management during the perfusion data analysis. Based on reference test data, the implementation was validated against a reference implementation. No differences were found in the calculated parameters. Conclusion: We developed open source software to analyse DCE-MRI perfusion data. The software is designed as plugin for the DICOM Workstation OsiriX. It features a clean GUI and provides a simple workflow for data analysis while it could also be seen as a toolbox providing an implementation of several recent compartment models to be applied in research tasks. Integration into the infrastructure of a radiology department is given via OsiriX. Results can be saved automatically and reports generated automatically during data analysis ensure certain quality control